Oil Cleanup/ Burnouts

[TheReefer]

So did a conversion of an old r22 system over to 407c and when performing the oil change the drain filter came out totally plugged, oil was black lookin like old motor oil. So in this instance when putting in new filter cores I used the HH cores for clean up and made a note to do a second change here in the next couple of weeks but I was curious what procedures anybody else would follow when encountering bad oil.

[TechmanTerry]

Is that the oil "screen" from the comp oil sump? What oil is in the comp? Do an Acid Test of the oil. Change the oil. Add a Changeable Core SL&LL FD's and retest after just a few days, not weeks. The oil and FD might have to be replaced a few times. Got a SGMI on this? What condition is the Cond Coil in?

[Galt]

keep changing it till it stays clean.

[pecmsg]

Those filters are going to plug up quickly with POE in the system, it acts as a cleaning agent inside.

Oil like that have a compressor handy, you'll be changing it shortly.

[71CHOPS]

You better put a suction filter on that system FAST.....that POE is gonna return every bit of crap from out in the system.

From the looks of that screen, You'll be putting another compressor in if you don't stay on top of it.

Make sure you have at least 20* at the compressor also.

[pecmsg]

FWIW
Copeland does not recommend POE in those compressors. I’ve seen 2 fail shortly after converting to POE. Not done by us and NO suction filter.

[Restaurant Mech]

This is EXACTLY why I don't convert old systems to 407c.
If it didn't have poe to start with it's either staying 22 or going to a drop in like mo99 that doesn't require an oil change.
And even using a drop in, I add a suction filter.
This system was already on it's way out by the look of the oil. The fingers will be pointing at the last guy to touch it.

[TheReefer]

Ya I'm aware of the possible problems with a 407c conversion and the customer was made aware before the job began but comparing the price of 200lbs of r22 vs 407c in todays world for a system that probably won't make it another 10 years regardless of what we put in it, that was the choice. the story with this place is an old customer of my current company acquired this building recently and they wanted it up and running. We committed to that with no warranties so if fingers are pointed no worries.

[71CHOPS]

FWIW
Copeland does not recommend POE in those compressors. I’ve seen 2 fail shortly after converting to POE. Not done by us and NO suction filter.

Interesting, doesn't every new recip. Come with POE now?

[71CHOPS]

Ya I'm aware of the possible problems with a 407c conversion and the customer was made aware before the job began but comparing the price of 200lbs of r22 vs 407c in todays world for a system that probably won't make it another 10 years regardless of what we put in it, that was the choice. the story with this place is an old customer of my current company acquired this building recently and they wanted it up and running. We committed to that with no warranties so if fingers are pointed no worries.

Put a suction filter on, with a desiccant core, until it's cleaned up.

Then make sure all your staging is working correctly, and you have correct superheat (at the compressor) during all stages of loading....that would give it a fighting chance to make it.

[pecmsg]

Interesting, doesn't every new recip. Come with POE now?

In the older ones.
I’ll find the bulletin

[TechmanTerry]

I'll bet you this system is going to need 3-4 oil changes and FD swap outs and maybe 3-4 Acid Test Kits and some labor.

[Dacman]

It’s likely not going to last long, but add acid away and multiple oil and drier changes,
Check your superheat and adjust the txv to drop the temps , 407 will run higher with less capacity.
You could Meg your changes to see if progress is being achieved?

[hvacker]

Got to ask, is there something nasty in the air there? Looks like not normal corrosion.
HH suction cores clean up really well. Get a shell so they can be replaced easily. Usually more than one.

[71CHOPS]

Always a good idea to put isolation ball valves on the filters, so you can recover and easily change without pulling charge.

If its a critical application, use two housings in parallel, so you can swap, and change filters without shutting the system down.

[hvacker]

Always a good idea to put isolation ball valves on the filters, so you can recover and easily change without pulling charge.

If its a critical application, use two housings in parallel, so you can swap, and change filters without shutting the system down.

If you do valve a drier this way, or with a bypass, include a relief valve. Closing the valves to the driers and opening a bypass could result in a hydro-static burst if the liquid refrigerant built up pressures and having no where to go. This might happen if the drier was restricted and the bypass was opened and left that way.
I used to run in to driers piped w/o a relief. I thought at the time it was the way to pipe them until I ran across a relief valve requirement
in a spec. After thinking about it I began to include them on the drier.
Just a thought.

[71CHOPS]

Very good point.

Another way to do it is to either leave the unused housing in a vacuum and isolated until needed.

Or you can close the upstream valve, but leave the downstream valve open on the unused housing. Then just open the upstream valve when you're ready to put it into service.

[Smilin Steve]

First drain? Or an oil change after the first one?

If first: what do the condenser coils look like? Is there a HP safety? Is it manual or automatic reset?

So did a conversion of an old r22 system over to 407c and when performing the oil change the drain filter came out totally plugged, oil was black lookin like old motor oil. So in this instance when putting in new filter cores I used the HH cores for clean up and made a note to do a second change here in the next couple of weeks but I was curious what procedures anybody else would follow when encountering bad oil.

[Smilin Steve]

What are the two lines connected to that external U-bend ?

So did a conversion of an old r22 system over to 407c and when performing the oil change the drain filter came out totally plugged, oil was black lookin like old motor oil. So in this instance when putting in new filter cores I used the HH cores for clean up and made a note to do a second change here in the next couple of weeks but I was curious what procedures anybody else would follow when encountering bad oil.